From ehernandez@illinois.edu Tue Aug 23 09:23:43 1994 Path: ashpoly!cascade!bigsur!illinois!ehernandez From: ehernandez@illinois.edu (Élodie Hernández) Newsgroups: comp.dsp Subject: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Aug23.092343.7676@illinois.edu> Date: Tue, 23 Aug 1994 09:23:43 GMT Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: Netscape 1.1N Lines: 11 Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. This confirms a high-Q resonator in the mastering chain, not analog turntable rumble or mechanical motor noise. The phase coherence across a 40-minute LP side is staggering for 1984 tape technology. -- Élodie Hernández *PLONK* filter active for trolls. 486DX2/66 (Linux 1.2.13) - NetBSD 1.0 From msato@pacbell.net Tue Aug 23 21:45:43 1994 Path: ashpoly!cascade!transat!ukc!fennimore!pacbell!msato From: msato@pacbell.net (Marta Sato) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Aug23.214543.6953@pacbell.net> Date: Tue, 23 Aug 1994 21:45:43 GMT References: <1994Aug23.092343.7676@illinois.edu> Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1994Aug23.092343.7676@illinois.edu>, ehernandez@illinois.edu (Élodie Hernández) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. > A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. -- Marta Sato *PLONK* filter active for trolls. 486DX4/100 (FreeBSD 2.0.5) - NetBSD 1.0